Marianita Guionson, administrative officer of the Navotas health department, said that Vic Marijuan, Achilles Hilasque, Romy Angeles, Ferdinand Lim and Aniano Garque, are now safe.
"The four only suffered nausea, but Marijuan, an oiler was injured but not that serious," she said.
The five were employees of Irma Fishing and Trading Co. on C-4 Road, Navotas. They were hospitalized after a gas leaked from the cooling room of the Fishport Ice Plant at around 8:37 a.m.
Roberto "Bobby" del Rosario, general manager of IFTC that operates the ice plant, allayed fears that the gas leak may be fatal, saying that ammonia was just a minor irritant.
But according to Dr. Arnel Rivera, of the Tondo Medical Center (TMC), the gas was toxic and very harmful.
Del Rosario, however, said that ammonia, like freon, is a gas component in any air-conditioning system now commonly used in households.
A team, led by Senior Inspector Melvin Laguros, intelligence and operations chief of the NCR-MO, was dispatched to the area on Wednesday after the National Capital Region-Maritime Office (NCR-MO) in Navotas, under Superintendent Demosthenes "Bu" Felix, was informed of the gas leak at the Fishport Ice Plant.
Police learned that the leak was caused by a simple technical problem.
Marijuan reportedly mistakenly opened the ammonia plug instead of an oil plug, causing the leak.
The high-pressured ammonia hit Marijuan, causing severe burns in his upper body.
He was rushed to a nearby hospital with four of his fellow workers who inhaled the toxic fume. The leak was, however, immediately contained.
The Maritime police were still conducting investigation into the case to find out any culpability on the part of the ice plant operator.
Meanwhile, the Department of Health (DOH) asked the public to take extra care in handling ammonia, following the gas leak in Navotas.
In its advisory, the DOH said the "permissible occupational health guideline" for ammonia has been set at 25 ppm for an eight hour-work period and a short term (15 minutes) exposure limit of 35 ppm."
Ammonia is used as household or industrial cleaners and refrigerants. The DOH maintained that exposure to high level of ammonia in air could be irritating to the skin, eyes, throat and lungs and could cause coughing and burns.
"If ammonia gets into the eyes, remove any contact lenses at once and irrigate immediately. If a person breathes in large amount of this chemical, move the exposed person to fresh air at once and perform artificial respiration," the DOH added. — With Sheila Crisostomo